Safety clutch for saw mandrels



Jan. 9, 1923.. 1,111,819.

R. MOORE.

SAFETY CLUTCH FOR SAW IVIANDRELS.

FILED DEC-1| 1920. 2 SHEETSSHEETff.

INVENTOR.

V k/ ATTORNEYJ Jan, 9; 1923,

R. P. MOORE. SAFETY CLUTCH FOB SAW MANDRELS.

FILED DEC-111920- 2 SHEETSSHEET 2 E 16' Q I23 '11 35' 1,0

- INVENTOR.

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ttpplicationfiled December It, lE-MUI. Elerial N0.

[[ 0 all whom may concern Be it known that L RALPH l5. ltloonn, a citizen of the United Eitates, residing at llllorrisville, in the county of Wake, State of l lorth Carolina, have. invented certain new and useful improvements in Safety Clutches tor Saw Mandrels; and I do hereby declare the following to be a full, clear; and exact description of the invention, such as will enable others skilled in the. art to which it appertains to make and use the same.

This invention has particularly to do with a clutch tor use in connection with saw machines tor stopping the saw.

It often happens that the sawyer sees nail or spike in thelog; and in such an event it is necessary to stop the machine before the saw has reached the nail or spike, and thus prevent injury to the teeth of the saw.

The present invention is a clutch which is so connected with the saw mandrel that the sawy'er can inm'iediately disengage the saw from the rotating wheel while the saw remains stationary in the kert in the log and the wheel continues to rotate. The device so constructed. that it can be easily and quickly operated. by the sawyer upon the simple movement oi a lever, which he actuates at the same time that he throws the lever which stops the teed.

tlther objects and advantages will be apparent -from the tolllowing description when taken in connection with the accompanying drawings.

.lln the drawings:

.liigure 1 is a view looking toward the edge face of the belt wheel which contains the novel clutch.

Figure 2 is a side elevation of the belt wheel showing the clutch mechanism in elevation, and in normal or operative position for the rotation of saw and mandrel.

Figure 3 is a similar view to that shown in Figure 2, but with the clutch thrown out to permit the saw to remain stationary in the kert of the log, and the wheel to continue its rotation.

Figure 4 is a horizontal transverse sectional view through the belt wheel and clutch mechanism, on the line 4-et of Fig; ure 3, which line passes through the open ings in the hub through which the lever actuating linlrs are disposed, the clutch beingin engaged position with the iiaiiige of the wheel.

Figure 5 is similar sectional view to that of Figure -l-, but with the clutch disengaged act with the flange otthe wheel. I particularly to the accompany inn drawings 10 represents a shaft on which isloosely rotatable the belt wheel or pulley 11, said pulley having the hub 14- and the circumferential flange 12 for engagement thereon ol? drive belt, not shown. A hub 14: on the shaft 10 has the radially and oppositely catendin arms 15, and pivotally connected to one face of the outer end of each arm is an end of one curved spring clutch arm or shoe 16, the outer or convex :taee oif which is arranged to lirictionally contact with the inner tace oi the flange oi the belt wheel or pulley 11. [is will be understood, these curved arms or shoes normally spring inwardly, away from the flange l2,

and are adapted to be brought into frictional engagement with the flange by a positive means which will be later described. The

other or free end of each of the arms 16 is formed with a slightly enlarged portion on one side of which is carried a small roller 1?. disc pivotolly mounted on the outer end portion of each arm l5 adjacent the pivoted end of the arm 16, is a circuim'ferentially extending curved lever 18. The pivotal end portion oil each lever 18 is disposed in allel relation to the spolres, and one edge face of the curved arm contacts with the he tore mentioned roller 1? so that when the lever is swung in a direction away from the center of the wheel, this portion of the lever, b its engagement with the roller, will force the curved arm outward into frictional engagement with the inner tace out the flange ot the wheel 11, whereby the mandrel and wheel will be clutched together.

Formed on the hub 14;, at diametrically opposite points, are the bosses or enlarge ments l9, and formed through each boss, in a direction longitudinally of the mandrel or shaft 10, is an opening 20. E llidable and rotatable on the shalt or mandrel 10 is a collar 21, having a circumferential groove 22 "for the reception oi: shitting yoke, not shown. Extending longitudinally from one end of the collar ill, and rigidly connected thereto, are the arms 25 which slidably engage in the openings 26. Pivotally connected to the inner end of each arm. 25, with in an opening 20,1is alinlt 2t". Threaded into each curved arm. or lever 18 is a steps 27,

which is pivotally connected with a link 26. Thus, as the arms are moved longitudinally in the openings 20 the links will cause the stems to move inwardly and outwardly, so that the levers 18 will be swung on their pivots to engage with and disengage from the rollers 17, and thereby move the clutch arms 16 into and out of frictional contact with the flange of the wheel 11. It will be noted, upon reference to Figure 4, that when the clutch arms 16 are in frictional engagement with the flange of the wheel, the links 26 stand perpendicular to the longitudinal axis oil? the mandrel, and will remain in such position while the mandrel and wheel rotate, but upon outward movement of the collar and arms 25, the links will be moved into positions oblique to the axis of the shaft or mandrel. This latter position permits the clutch arms 16 to flex inwardly away from the flange of the wheel, and thereby release. the wheel from the mandrel, with the result that the saw, which is secured to the shaft 10 will remain stationary in the kerf in the log, while the wheel 11 continues to rotate. The saw is thus stopped at the proper time to avoid contact with a nail or spike, which the sawyer may see in the log just ahead of the saw. The outer faces of the curved arms 16 are provided with asbestos as shown at 16'.

What is claimed is: The combination with the saw mandrel, of a sawing machine, of a flanged wheel mounted on the mandrel, a hub keyed on the shaft and disposed within the flange 01'' the wheel, said hub having radiating arms. curved flexible clutch arms pivotally carried by the radiating arms and having laterally extending rollers on their free ends, levers pivotally mounted on the radiating arms and normally engaged with the said rollers. a collar slidahle on the said mandrel and having longitudinally extending arms. the said hub having longitmlinal openings receiving the longitudinally extending arms slidabl i therethrough, stems extending radially with respect to the said wheel and adjustahlv engaged with the lovers, links pivot-ally connecting the longitudinally extending arms and the said stems, and means for moving the collar.

In testimony whereof, I affix my signature, in the presence of two witnesses.

l'IATJPI'l l MOON It.

lVit-nesses T. C. C'RoMrroN, S. BOWLING. 

